Simplify logic by structure

11 files changed, 239 insertions, 45 deletions

diff --git a/Makefile b/Makefile
index eee72d1..2a0167a 100644
--- a/Makefile
+++ b/Makefile
@@ -10,8 +10,8 @@ clean:
 %.o: %.c
 	$(CC) -c $(CFLAGS) $(CPPFLAGS) $< -o $@
 
-client: client.o common.o
+client: client.o util.o
 	$(CC) -o $@ $^
 
-server: server.o common.o
+server: server.o util.o eventloop.o tsocket.o
 	$(CC) -o $@ $^
diff --git a/client.c b/client.c
index 9e3a421..0b9cbfe 100644
--- a/client.c
+++ b/client.c
@@ -6,7 +6,7 @@
 #include <stdbool.h>
 #include <stdio.h>
 
-#include "common.h"
+#include "util.h"
 
 int
 main()
@@ -24,7 +24,7 @@ main()
     if (connect(sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) == -1)
         panic("socket connect error");
 
-    while (true) {
+    for (;;) {
         char buf[1024];
         bzero(&buf, sizeof(buf));
         scanf("%s", buf);
diff --git a/common.c b/common.c
deleted file mode 100644
index 154e60d..0000000
--- a/common.c
+++ /dev/null
@@ -1,8 +0,0 @@
-#include <stdlib.h>
-#include <stdio.h>
-
-void panic(const char *msg)
-{
-    perror(msg);
-    exit(EXIT_FAILURE);
-}
diff --git a/common.h b/common.h
deleted file mode 100644
index fbb7267..0000000
--- a/common.h
+++ /dev/null
@@ -1 +0,0 @@
-void panic(const char *);
diff --git a/eventloop.c b/eventloop.c
new file mode 100644
index 0000000..f79114d
--- /dev/null
+++ b/eventloop.c
@@ -0,0 +1,39 @@
+#include <stdlib.h>
+#include <sys/epoll.h>
+#include "eventloop.h"
+
+struct eventLoop *eventLoopNew()
+{
+    int epollfd = epoll_create1(0);
+    if (epollfd == -1)
+        return NULL;
+
+    struct eventLoop *eventLoop = malloc(sizeof(*eventLoop));
+    eventLoop->epollfd = epollfd;
+    eventLoop->size = EVENT_LOOP_MAX_EVENTS;
+
+    return eventLoop;
+}
+
+int eventLoopAddSocket(struct eventLoop *el, struct tsocket *sock, int flag)
+{
+    struct epoll_event ev;
+    ev.events = flag;
+    ev.data.fd = sock->fd;
+
+    // TODO: How the fd ranges? Will it be larger than the MAX_EVENTS?
+    el->socks[sock->fd] = sock;
+
+    return epoll_ctl(el->epollfd, EPOLL_CTL_ADD, sock->fd, &ev);
+}
+
+int eventLoopWait(struct eventLoop *el, int timeout)
+{
+    return epoll_wait(el->epollfd, el->events, el->size, timeout);
+}
+
+struct tsocket *eventLoopGetSocket(struct eventLoop *el, int index)
+{
+    int fd = el->events[index].data.fd;
+    return el->socks[fd];
+}
diff --git a/eventloop.h b/eventloop.h
new file mode 100644
index 0000000..39c05d5
--- /dev/null
+++ b/eventloop.h
@@ -0,0 +1,22 @@
+#include <sys/epoll.h>
+
+#include "tsocket.h"
+
+#ifndef __EVENT_LOOP_H
+#define __EVENT_LOOP_H
+
+#define EVENT_LOOP_MAX_EVENTS 1024
+
+struct eventLoop {
+    int epollfd;
+    struct epoll_event events[EVENT_LOOP_MAX_EVENTS];
+    struct tsocket *socks[EVENT_LOOP_MAX_EVENTS];
+    int size;
+};
+
+struct eventLoop *eventLoopNew();
+int eventLoopAddSocket(struct eventLoop *el, struct tsocket *sock, int flag);
+int eventLoopWait(struct eventLoop *el, int timeout);
+struct tsocket *eventLoopGetSocket(struct eventLoop *el, int index);
+
+#endif
diff --git a/server.c b/server.c
index 63f3062..1e3ad68 100644
--- a/server.c
+++ b/server.c
@@ -7,51 +7,83 @@
 #include <stdio.h>
 #include <sys/types.h>
 #include <unistd.h>
+#include <sys/epoll.h>
+#include <errno.h>
 
-#include "common.h"
+#include "eventloop.h"
+#include "tsocket.h"
+#include "util.h"
+
+#define READ_BUFFER_SIZE 1024
+
+void handleEvent(struct tsocket *sock)
+{
+    char buf[READ_BUFFER_SIZE];
+    ssize_t n_read_bytes;
+
+    for (;;) {
+        n_read_bytes = read(sock->fd, buf, sizeof(buf));
+        if (n_read_bytes > 0) {
+            printf("message from conn %d: %s\n", sock->fd, buf);
+            write(sock->fd, buf, sizeof(buf));
+        } else if (n_read_bytes == 0) {
+            printf("conn %d disconnected\n", sock->fd);
+            tsocketDelete(sock);
+            break;
+        } else if (n_read_bytes == -1) {
+            if (errno == EAGAIN || errno == EWOULDBLOCK)
+                break;
+        }
+    }
+}
 
 int main()
 {
-    int sockfd = socket(AF_INET, SOCK_STREAM, 0);
-    if (sockfd == -1)
+    struct tsocket *sock = tsocketNew();
+    if (sock == NULL)
         panic("socket creation error");
 
-    struct sockaddr_in serv_addr;
-    bzero(&serv_addr, sizeof(serv_addr));
-    serv_addr.sin_family = AF_INET;
-    serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
-    serv_addr.sin_port = htons(8888);
-
-    if (bind(sockfd, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) == -1)
+    if (tsocketBind(sock, "127.0.0.1", 8888) == -1)
         panic("socket bind error");
 
-    if (listen(sockfd, SOMAXCONN) == -1)
+    if (tsocketListen(sock) == -1)
         panic("socket listen error");
 
-    struct sockaddr_in clnt_addr;
-    socklen_t clnt_addr_len = sizeof(clnt_addr);
-    bzero(&clnt_addr, sizeof(clnt_addr));
+    struct eventLoop *el = eventLoopNew();
+    if (el == NULL)
+        panic("eventloop creation");
 
-    int clnt_sockfd = accept(sockfd, (struct sockaddr *)&clnt_addr, &clnt_addr_len);
-    if (clnt_sockfd == -1)
-        panic("socket accept error");
+    if (eventLoopAddSocket(el, sock, EPOLLIN) == -1)
+        panic("eventloop add fd");
 
-    printf("New client fd %d, ip: %s, port: %d\n", clnt_sockfd, inet_ntoa(clnt_addr.sin_addr), ntohs(clnt_addr.sin_port));
+    int nfds;
+    struct tsocket *conn_sock;
+    for (;;) {
+        nfds = eventLoopWait(el, -1);
+        if (nfds == -1)
+            panic("eventloop wait");
 
-    while (true) {
-        char buf[1024];
-        bzero(&buf, sizeof(buf));
-        ssize_t n_read_bytes = read(clnt_sockfd, buf, sizeof(buf));
-        if (n_read_bytes > 0) {
-            printf("message from client fd %d: %s\n", clnt_sockfd, buf);
-            write(clnt_sockfd, buf, sizeof(buf));
-        } else if (n_read_bytes == 0) {
-            printf("client fd %d disconnected\n", clnt_sockfd);
-            close(clnt_sockfd);
-            break;
-        } else if (n_read_bytes == -1) {
-            close(clnt_sockfd);
-            panic("socket read error");
+        for (int i = 0; i < nfds; i++) {
+            if (eventLoopGetSocket(el, i) == sock) {
+                conn_sock = tsocketAccept(sock);
+                if (conn_sock == NULL)
+                    panic("socket accept error");
+
+                printf("New client fd %d, ip: %s, port: %d\n", 
+                        conn_sock->fd, conn_sock->addr, conn_sock->port);
+
+                if (setblocking(conn_sock->fd, false) == -1) {
+                    close(conn_sock->fd);
+                    continue;
+                }
+                
+                if (eventLoopAddSocket(el, conn_sock, EPOLLIN | EPOLLET) == -1)
+                    panic("eventloop add fd: conn_sockfd");
+
+                tsocketDelete(conn_sock);
+            } else {
+                handleEvent(eventLoopGetSocket(el, i));
+            }
         }
     }
 }
diff --git a/tsocket.c b/tsocket.c
new file mode 100644
index 0000000..d1d0368
--- /dev/null
+++ b/tsocket.c
@@ -0,0 +1,60 @@
+#include <arpa/inet.h>
+#include <stdlib.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#include "tsocket.h"
+
+struct tsocket *
+tsocketNew()
+{
+    int fd = socket(AF_INET, SOCK_STREAM, 0);
+    if (fd == -1)
+        return NULL;
+
+    struct tsocket *sock = malloc(sizeof(*sock));
+    sock->fd = fd;
+
+    return sock;
+}
+
+int tsocketBind(struct tsocket *sock, const char *addr, int hostport)
+{
+    struct sockaddr_in sock_addr;
+    sock_addr.sin_family = AF_INET;
+    sock_addr.sin_addr.s_addr = inet_addr(addr);
+    sock_addr.sin_port = htons(hostport);
+
+    sock->addr = addr;
+    sock->port = hostport;
+
+    return bind(sock->fd, (struct sockaddr *)&sock_addr, sizeof(sock_addr));
+}
+
+int tsocketListen(struct tsocket *sock)
+{
+    return listen(sock->fd, SOMAXCONN);
+}
+
+struct tsocket *tsocketAccept(struct tsocket *sock)
+{
+    struct sockaddr_in addr;
+    socklen_t addr_len = sizeof(addr);
+
+    int fd = accept(sock->fd, (struct sockaddr *)&addr, &addr_len);
+    if (fd == -1)
+        return NULL;
+
+    struct tsocket *conn_sock = malloc(sizeof(*conn_sock));
+    conn_sock->fd = fd;
+    conn_sock->addr = inet_ntoa(addr.sin_addr);
+    conn_sock->port = ntohs(addr.sin_port);
+
+    return conn_sock;
+}
+
+void tsocketDelete(struct tsocket *sock)
+{
+    close(sock->fd);
+    free(sock);
+}
diff --git a/tsocket.h b/tsocket.h
new file mode 100644
index 0000000..5a8826c
--- /dev/null
+++ b/tsocket.h
@@ -0,0 +1,18 @@
+#include <netinet/in.h>
+
+#ifndef __TSOCKET_H
+#define __TSOCKET_H
+
+struct tsocket {
+    int fd;
+    const char *addr;
+    int port;
+};
+
+struct tsocket *tsocketNew();
+int tsocketBind(struct tsocket *sock, const char *addr, int hostport);
+int tsocketListen(struct tsocket *sock);
+struct tsocket *tsocketAccept(struct tsocket *sock);
+void tsocketDelete(struct tsocket *sock);
+
+#endif
diff --git a/util.c b/util.c
new file mode 100644
index 0000000..a44cc66
--- /dev/null
+++ b/util.c
@@ -0,0 +1,22 @@
+#include <stdlib.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+
+#include "util.h"
+
+void panic(const char *msg)
+{
+    perror(msg);
+    exit(EXIT_FAILURE);
+}
+
+int setblocking(int fd, bool blocking)
+{
+    u_long mode = blocking ? 0 : 1;
+    if (ioctl(fd, FIONBIO, &mode) == -1)
+        return ERROR;
+
+    return OK;
+}
diff --git a/util.h b/util.h
new file mode 100644
index 0000000..6e9c8cf
--- /dev/null
+++ b/util.h
@@ -0,0 +1,10 @@
+#ifndef __UTIL_H
+#define __UTIL_H
+
+#define ERROR -1
+#define OK 0
+
+void panic(const char *);
+int setblocking(int fd, bool blocking);
+
+#endif